Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/06—Non-macromolecular additives organic
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
  • C09J133/04—Homopolymers or copolymers of esters
  • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09J133/08—Homopolymers or copolymers of acrylic acid esters
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
  • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature

Definitions

• the present invention relates to an optically transparent adhesive sheet.
• image display modules of electronic devices such as mobile handheld devices, computer displays and touch panels
• glass or plastic films are laminated as surface protective layers.
• This surface protection layer is fixed to the image display module or touch panel by applying a frame-shaped tape or adhesive to the margin outside the image display portion or outside the active area of the touch panel. As a result, a gap is formed between the active area of the image display portion or the touch panel and the surface protective layer.
• exemplary transparent materials include, but are not limited to, optical adhesive films (OCA films), pressure sensitive adhesives, adhesives, silicon gels, and the like.
• OCA films optical adhesive films
• Silicone gels have reliability problems due to their low adhesion.
• the pressure-sensitive adhesive for example, the pressure-sensitive adhesive sheet
• the pressure-sensitive adhesive sheet is capable of re-lamination in spite of sufficiently high adhesion, but it is difficult to apply uniformly due to the liquid type by the solvent, and lifted by the remaining solvent. There is a problem that a phenomenon occurs.
• the surface of the adherend such as an image display module, optical member or surface protective layer
• the surface of the surface protective layer in particular in contact with an adhesive film or adhesive sheet, is often subjected to printing for decorative or shading purposes.
• the printed portion generates a step of at least 10 ⁇ m in height on the surface of the surface protective layer.
• One potential problem in laminating an image display module or touch panel with a surface protective layer using an optical adhesive film is that the optical adhesive film may not be sufficiently matched to the stage and there may be gaps on or around the stage. It can be triggered.
• an object of the present invention is to provide an optically transparent adhesive sheet having excellent end embedding properties and step resilience, and minimizing lifting phenomenon from the surface of the adherend after curing.
• the present invention is an optically transparent adhesive sheet comprising a resin syrup and a photoinitiator prepared by partially polymerizing a (meth) acrylate monomer,
• the optically transparent adhesive sheet has a storage modulus after primary UV crosslinking at 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 ° C. and 1 Hz, and 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 ° C. and 1 Hz, It provides an optically transparent adhesive sheet having a 25 ° C. storage modulus increase rate after curing after the second ultraviolet crosslinking is 10 to 100% relative to the 25 ° C. storage modulus after the first ultraviolet crosslinking.
• the present invention provides a composition for producing the above-mentioned optically transparent adhesive sheet.
• the present invention provides a flat panel display device including the optically transparent adhesive sheet described above.
• the storage modulus after primary UV crosslinking is 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 ° C. and 1 Hz, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 ° C. and 1 Hz,
• the 25 ° C. storage modulus increase after curing after crosslinking satisfies 10 to 100% of the 25 ° C. storage modulus after the first ultraviolet crosslinking, so that the end buried property and the step resilience are excellent, and are lifted from the surface of the adherend after curing. It is possible to provide an optically transparent adhesive sheet with minimal phenomenon.
• the present invention relates to an optically transparent adhesive sheet, a composition for manufacturing the same, and a flat panel display device including the same.
• the optically transparent adhesive sheet of the present invention may be an inorganic film.
• the composition of the present invention may be one containing (meth) acrylate syrup, photoinitiator and (meth) acrylate monomer.
• the optically transparent adhesive sheet of the present invention may include a (meth) acrylic copolymer, a photoinitiator and an acrylate monomer, and in the present invention, that the optically transparent adhesive sheet includes the composition may mean that the composition is prepared from the composition. have.
• the optically transparent adhesive sheet of the present invention made of the composition has a storage modulus of 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 °C and 1 Pa, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 °C and 1 Pa
• the 25 ° C. storage modulus increase after curing satisfies 10 to 100% of the 25 ° C. storage elastic modulus after the first ultraviolet crosslinking, so that the end buried property and the step resilience are excellent, and the adhesive after curing The lifting phenomenon from the surface of can be minimized.
• the present invention has a storage modulus of 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 ° C. and 1 Hz, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 ° C. and 1 Hz, and 25 after curing after secondary UV crosslinking.
• °C storage elastic modulus increase rate is less than 10% of 25 °C storage elastic modulus after the first ultraviolet cross-linking is insufficient cohesion in the internal pressure-sensitive adhesive due to bubbles under the durability conditions, if the 100% or more cohesive strength is excessively increased and the adhesive Adhesion to and lowers the durability.
• the durability can be secured by increasing the internal crosslinking density of the adhesive and improving the appropriate cohesion. do.
• (meth) acrylate means “acrylate", “methacrylate” or both.
• (meth) acrylate syrup when included, it can contribute to the cohesion, adhesion and durability of the adhesive.
• the (meth) acrylate syrup of the present invention may comprise i) an acrylate comprising a hydroxy group and ii) a monofunctional (meth) acrylate monomer.
• the i) acrylate monomer including a hydroxyl group it may contribute to the improvement of cohesion and adhesion.
• the i) acrylate containing a hydroxy group is not limited in kind as long as it includes a hydroxy group
• the alkyl acrylate monomer containing a hydroxy group is specifically, for example, 2-hydroxyethyl acrylate, 2-hydroxy Propyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate, 8-hydroxyoctyl acrylate, 2-hydroxyethylene glycol acrylate and 2-hydroxypropylene Glycol acrylate and the like.
• the ii) monofunctional (meth) acrylate monomer is not limited as long as it is a monofunctional monomer known in the art, specifically, for example, ethylhexyl (meth) acrylate, dodecyl (meth) Acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) Acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylhexyl ( Meth) acrylate, 2-ethylbutyl (meth) acrylate, n-oct
• the i) acrylate containing a hydroxy group may include 5 to 20% by weight relative to the total weight of the copolymer comprising the i) acrylate containing a hydroxy group and the ii) monofunctional (meth) acrylate monomer, 5 If it is less than the weight%, the durability reliability may be lowered, such as cohesive failure occurs under high temperature and / or high humidity conditions, and if it exceeds 20% by weight, wettability and adhesion may be reduced due to the decrease in compatibility.
• the (meth) acrylate syrup may have a weight average molecular weight of 600,000 or more and 1 million or less, more preferably 600,000 or more and 800,000 or less.
• the weight average molecular weight of the (meth) acrylate syrup of the present invention satisfies the above range, it can be expected to improve adhesion characteristics, wettability, and durability.
• the optically transparent adhesive sheet of the present invention includes a photoinitiator in order to efficiently induce the reaction of the radical polymerizable group.
• the photoinitiator is not particularly limited as long as the photoinitiator is a general initiator capable of generating radicals by irradiation with ultraviolet rays and thus may initiate photopolymerization, and photopolymerization initiators known in the art may be used. Specifically, a benzoin initiator, a hydroxy ketone initiator, an amino ketone initiator, and / or a phosphine oxide initiator, etc.
• the photoinitiator When the photoinitiator is mixed with a (meth) acrylate syrup, it is selected from the group consisting of a benzoin initiator, a benzophenone initiator, a hydroxyketone initiator, an amino ketone initiator, and / or a phosphine oxide initiator. It may include more than one species.
• 2,2-dimethoxy-1,2-diphenylethan-1-one (2,2-Dimethoxy-1,2-diphenylethan-1-one), diphenyl (2,4,6-trimethylmenzo Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide), hydroxy cyclohexyl phenyl ketone, hydroxy methyl phenyl propane, benzoylformic acid, 1,4-dibenzoylbenzene, benzyl, benzo It may include two or more selected from the group consisting of phenone acrylic (VISIOMER6973, Evonik) and the like.
• phenone acrylic VISIOMER6973, Evonik
• the photoinitiator may be included 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight when the total amount of the acrylate monomer and the monofunctional (meth) acrylate monomer including the hydroxy group is 100 parts by weight.
• the photoinitiator may be included in 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight based on 100 parts by weight of (meth) acrylate syrup.
• Method for producing an optically transparent adhesive sheet of the present invention can be carried out by a method commonly used in this field except as described above. At this time, molecular weight regulators, catalysts and the like used in this field may also be used without limitation.
• the optically transparent adhesive sheet of the present invention may have a gel fraction of 30 to 70%. If the gel fraction satisfies the above range, the effects of durability, end filling and step resilience can also be improved.
• the method of applying the optically transparent adhesive sheet of the present invention is not particularly limited, and after applying the optically transparent adhesive sheet, it is cured through light irradiation.
• the ultraviolet irradiation may be performed using a means such as a high pressure mercury lamp, an electrodeless lamp or a xenon lamp.
• an appropriate aging process may be conducted to induce reaction of the functional group of the crosslinking agent in the composition with the thermosetting functional group of the polymer, and the conditions in the process are not particularly limited as long as an appropriate crosslinking reaction can occur. .
• an optical film such as a polarizing film, a retardation film, an anti-glare film, a wide viewing angle compensation film, or a brightness enhancement film is laminated on each other, or the optical film or the laminate thereof is displayed on a display panel or the like. It can be used to attach to the same adherend.
• optically transparent adhesive sheet of the present invention can be preferably used in a flexible display device.
• the manufacturing method of the optically transparent adhesive sheet can be used without limitation methods known in the art.
• a flat panel display device comprising an optically transparent adhesive sheet formed of the optically transparent adhesive sheet composition of the present invention.
• the flat panel display is more preferably a flexible display device.
• Test Example 1 Evaluation of weight average molecular weight and molecular weight distribution
• the weight average molecular weight and molecular weight distribution of (meth) acrylate syrup were measured on condition of the following using GPC. The measurement result was converted into the calibration curve using standard polystyrene of Agilent system.
• the pressure-sensitive adhesive composition was prepared by mixing the content of the (meth) acrylate syrup and the photoinitiator of the preparation example in the composition of Table 2 below.
• the pressure-sensitive adhesive composition prepared above was applied on a release film coated with a silicone release agent to have a thickness of 150 ⁇ m, the release film was bonded thereto, and a pressure-sensitive adhesive sheet was prepared. After the first UV irradiation, the sheet was completed.
• the storage elastic modulus of the said adhesive sheet measured the storage elastic modulus in # 25 degreeC and 70 degreeC using the viscoelasticity measuring apparatus (MCR-301, "Anton Paar company). More specifically, the sample size of the adhesive layer is 30 mm long and 30 mm wide, and the sample is bonded to the glass plate and bonded to the measuring tip. It measured by the conditions of the temperature increase rate of 5 degree-C / min, and calculated
• the storage modulus after primary UV curing and the storage modulus after secondary UV curing are shown in Table 2 below.
• Example Comparative example One 2 3 4 5 6 7 One 2 3 (Meth) acrylate syrup (weight part) Kinds A1 A1 A1 A1 A2 A3 A4 A5 A1 A1 content 100 100 100 100 100 100 100 100 100 100 100 Photoinitiator (parts by weight) DMPA 1.0 1.0 1.0 2.0 1.0 1.0 TPO 1.0 1.0 1.0 1.0 1.0 1.0 B1 1.0 1.0 1.0 1.0 1.0 3.0 1.0 B2 1.0 B3 1.0 UV irradiation amount (J / cm 2 ) Primary 3 3 3 3 3 3 3 3 3 3 3 3 3 3 One Secondary 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 One Storage modulus after primary UV curing (MPa, 1Hz) 25 °C 1.5 1.7 1.8 1.8 2.5 3.2 4.1 0.5 1.3 0.85 70 °C 0.066 0.068 0.063 0.064 0.072 0.078 0.081 0.037 0.058 0.032 Storage modulus after secondary UV curing (MPa
• the polarizing plate with an optically transparent adhesive inorganic film manufactured by Examples 1-7 and Comparative Examples 1-3 was cured at 23 degreeC and 65% RH for 1 day.
• About 0.25 g of an adhesive layer is affixed on the fixed 250 mesh wire mesh (100 mm x 100 mm), and it wraps so that a gel powder may not leak.
• the wire mesh is immersed in ethyl acetate solution for 3 days.
• the immersed wire mesh is taken out, washed with a small amount of ethyl acetate solution, dried at 120 ° C. for 24 hours, and weighed.
• the gel fraction was calculated by the following equation 1 using the measured weight.
• A is the weight of the wire mesh (g)
• B is the weight of the wire mesh with the adhesive layer (BA: adhesive weight, g)
• C is the weight of the dried wire mesh after immersion (CA: weight of the gelled resin, g )being].
• PET50 polyethylene terephthalate film
• a mold having a thickness of 50 ⁇ m made of cut PET50 was placed on the remaining PET 100 on the peeled PET100 and bonded to another PET100 (PET100 / adhesive / PET50 / PET100 configuration).
• Example Comparative example One 2 3 4 5 6 7 One 2 3 Gel fraction after the first curing 45 51 62 55 61 64 42 82 0 43 Step filling ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ Durability (85 °C, 85% RH) O ⁇ O ⁇ ⁇ O ⁇ ⁇ ⁇ ⁇ ⁇ ⁇
• the storage modulus of the present invention is 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 ° C. and 1 Hz, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 ° C. and 1 Hz, and 25 after curing after secondary UV crosslinking.
• the durability was excellent. Meaning to have, the adhesion is improved, it was confirmed that the effect of the end embedding and step resilience is also excellent.
• the storage modulus of the present invention is 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 °C and 1 Pa, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 °C and 1 Pa, curing after secondary UV crosslinking
• the 25 ° C. storage modulus increase rate did not satisfy 10-100% of the 25 ° C. storage modulus after the first ultraviolet crosslinking
• durability was poor. It was confirmed that the adhesion was poor due to poor durability, and this resulted in almost no effect of end embedding and step breakability.
• Comparative Example 3 in which the primary UV storage elastic modulus was not satisfied due to a decrease in the reaction rate due to a low amount of light, was poor in both step filling properties and durability.
• the storage modulus after primary UV crosslinking is 1.0 ⁇ 10 6 to 1.0 ⁇ 10 7 Pa at 25 ° C. and 1 Hz, 5.0 ⁇ 10 4 to 5.0 ⁇ 10 5 Pa at 70 ° C. and 1 Hz,
• the 25 ° C. storage modulus increase after curing after crosslinking satisfies 10 to 100% of the 25 ° C. storage modulus after the first ultraviolet crosslinking, so that the end buried property and the step resilience are excellent, and are lifted from the surface of the adherend after curing. It is possible to provide an optically transparent adhesive sheet with minimal phenomenon.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)
• Adhesive Tapes (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 2017
  • 2017-04-28 KR KR1020170055262A patent/KR101855041B1/ko active IP Right Grant
• 2018
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